Research: How women change if given the male testosterone hormone?

Scientists have discovered that the hormone testosterone, which makes men physically strong and aggressive, seems also to be connected to cynicism and a lack of trust in others. They found that when it was given to women it appeared to "harden them up" and made them less open and more vigilant.
 
Historically for women it was important to be co-operative and sociable in order to survive whereas for men it was more important to be able to fight.

Men therefore evolved with more testosterone than women in order to make them bigger, stronger and more aggressive. It also seems to have made them more wary and to constantly "watch their back" for danger.

For the study, Dr Jack van Honk, a psychologist at Cape Town University, said that testosterone increases social vigilance in order to prepare them for competition and fights for resources. They said: "In the same way that we have evolved capacities to help others, we have also evolved capacities to deceive and cheat.

"Thus, those who are willing to believe what others say, or fail to probe the motivations underlying their actions, may fall prey to considerable economic and social costs.

"Consequently, testosterone increased social vigilance in trusting humans, presumably to better prepare them for the hard-edged competition over status and valued resources."

In order to test the theory researchers gave testosterone pills and dummy pills to 24 women aged about 20 and then asked them to rate the trustworthiness of strangers' faces. The scale went from -100 for very untrustworthy to +100 for very trustworthy.

The half of volunteers who rated faces as most honest after the placebo scored the photographs an average 10 points – or five per cent – lower after ingesting testosterone. The researchers, whose findings are published in Proceedings of the National Academy of Sciences, said the research showed that testosterone "down regulates interpersonal trust".

"Naive, trusting humans run a much greater risk of being misguided and deceived by others," they said.

"The attribution of trust toward unfamiliar others was especially decreased in subjects who run the greatest risk of being misled by others, that is, those who grant trust easily.

"These findings provide insight into the hormonal regulation of human sociality by showing the hormone testosterone down-regulates interpersonal trust in an adaptive manner." 


/Telegraph.co.uk/